The present invention relates to a method of producing an anti-reflection film with a desired reflectivity used for a display such as a CRT (cathode ray tube) screen and a PDP (plasma display panel) screen.
An anti-reflection film is generally formed of a plurality of layers having alternately laminated low-reflectivity layers and high-reflectivity layers on a transparent synthetic resin sheet. The anti-reflection film is attached to a CRT screen or a PDP screen with a transparent adhesive (including a self-attaching adhesive). When such an anti-reflection film is attached to the PDP or CRT, the synthetic resin sheet faces outside (side away from the CRT or PDP, or side exposed to the atmosphere).
In order to calculate reflectivity and transmittance of an anti-reflection film comprising multi-layer films, there are known methods such as vector method, Smith chart and Kard chart. In the methods for calculating the reflectivity and transmittance of an anti-reflection film, characteristic matrices M1, M2, M3, to Mk are determined for each layer using complex refractive indices and optical thicknesses, and then the characteristic matrix M is determined from the product of the characteristic matrices M1, M2, M3, to Mk. In designing the anti-reflection film, the refractive index and thickness of each layer are selected so that a desired reflectivity is obtained over a given wavelength range.
However, it is difficult to accurately calculate the characteristic matrix due to the complicated characteristic matrices and to obtain an optimum value.
In view of the problem, the present invention has been made, and an object of the invention is to provide a method for producing an anti-reflection film with a desired reflectivity.
Further objects and advantages of the invention will be apparent from the following description of the invention.